The invention relates to a vehicle roof module, in particular for motor vehicles.
Vehicle roof modules which are made separately from the vehicle bodywork and only connected with the vehicle bodywork on the assembly belt at the car factory are becoming increasingly popular in particular owing to a considerable reduction in assembly times on the assembly belt. If such vehicle roof modules are provided with an integral sunroof unit, separate manufacture opens up the advantageous possibility of checking functioning of the preassembled sunroof unit before the roof module is connected with the bodywork.
In the case of a known vehicle roof module of this type (DE 197 09 016 A1, FIGS. 9, 11), a reinforcing frame surrounding the roof opening is foamed into the plastics foam of the inner shell in such a way that the sunroof may be attached thereto. This construction fulfils all requirements with regard to strength and performance. However, vehicle roof modules of the construction in question need also to be as lightweight as possible, without suffering any loss in strength and/or performance, in order to reduce the weight of the vehicle and assist in handling of the vehicle roof module.
The object of the invention is therefore to provide a vehicle roof module of the type indicated above, having an integral sunroof unit and a comparatively low weight.
This object is achieved according to the invention by a vehicle roof module having a sunroof frame attached to an inner shell at a plurality of points around the roof opening by elements present only at these points and connected firmly therewith.
It was found that, when the features according to the invention are applied, foaming-in of a reinforcing and stiffening frame into the inner shell at the periphery of the roof opening, which frame increases the weight of the roof module, may be omitted because, in the construction according to the invention, on the one hand the inner shell foamed onto the rigid roof skin, in particular if said inner shell is provided with a fiber reinforcement or the like dispersed in the plastics foam, and on the other hand the sunroof frame, after attachment thereof according to the invention, reinforce and stiffen the roof module sufficiently in the area of the roof opening.
The term xe2x80x9csunroofxe2x80x9d, used here alone or in phrases, is intended, for the purposes of the present invention, to cover not only designs in which the cover may be slid under the fixed rear roof surface to uncover the roof opening after lowering of its rear edge but also sliding/lifting sunroofs, in which the cover may additionally be swivelled from its closed position about a swivel axis provided in the vicinity of its front edge so as to project above the fixed roof surface. Front-hinged covers of the ventilation shutter type and sliding sunroofs in which the cover may be slid partially over the rear fixed roof surface to uncover the roof opening after lifting of its rear edge are also included. This applies to all designs comprising a sunroof frame attached beneath the fixed roof surface.
Various embodiments are proposed for the construction of the fastening elements. Thus, in some embodiments, the elements may consist of threaded elements foamed into the inner shell, onto which elements a flange of the sunroof frame is screwed. These threaded elements may comprise either internal or external threads, such that the sunroof frame is screwed on by means of either screws or nuts.
In some other embodiments there are metal ties foamed into the plastics foam of the inner shell, which ties have bendable tongues which pass through corresponding openings in a flange of the sunroof frame. The bendable tongues are bent round behind the flange, thereby pressing the flange against the inner shell. These fastening elements allow particularly quick assembly of the sunroof frame.
Some further embodiments dispense with separate or separately foamed-in fastening elements, by forming the elements from the plastics foam of the inner shell itself during back-filling of the rigid roof skin with foam, such that they are in one piece with the inner shell, and fixing the sunroof frame to the inner shell by passing said elements through corresponding openings in the flange of the sunroof frame. In a first variant, which also allows quick assembly of the sunroof frame, said fixing is achieved by providing the relevant foamed elements with a clip-type construction, such that they may snap in resiliently behind the flange. In a second variant, the foamed elements are constructed as hot rivets, wherein the elements are provided with a rivet head formed by heating and upsetting after passage through the openings in the flanges.
To achieve attachment of the sunroof frame to the inner shell with simultaneous provision of the necessary spacing of the sunroof frame from the fixed roof skin, it is not necessary to increase the thickness of the entire inner shell of the roof module in the area of the roof opening, but instead, it can be sufficient to provide the inner shell with pedestal elements at the attachment points, which pedestal elements are formed from the plastics foam during back-filling of the fixed roof skin with foam and against which the sunroof frame lies with its fastening flange. The fastening elements are then arranged on these pedestal elements. These pedestal elements do not have to take the form of continuous ribs or the like, foamed material-saving rib portions or even peg-shaped elements at the attachment points being sufficient to achieve reliable, roof module-stiffening attachment of the sunroof frame.
As a continuation of the concept of simplified attachment, the inner shell of the roof module may be attached to the bodywork frame in the same way as the sunroof frame is attached to the inner shell.